An ACN is the 9-digit number ASIC gives a company when it registers. An ARBN is the number ASIC gives a foreign company registered to do business in Australia (a branch). An ABN is an 11-digit number issued by the Australian Business Register (the ATO) for tax and business dealings; a company's ABN is often its ACN with 2 extra digits in front.
Australia uses three different registration numbers for companies, and foreign businesses often mix them up. Which ones you get depends on whether you set up an Australian company or register your overseas company here.
The three numbers at a glance
| ACN | ARBN | ABN | |
|---|---|---|---|
| Stands for | Australian Company Number | Australian Registered Body Number | Australian Business Number |
| Issued by | ASIC | ASIC | The Australian Business Register (part of the ATO) |
| Who gets it | Every Australian company, such as a Pty Ltd | A foreign company registered to carry on business in Australia (a branch), and registered Australian bodies | Any entity carrying on an enterprise in Australia, including companies and many foreign businesses |
| Digits | 9 | 9 | 11 |
| Used for | Identifying the company with ASIC | Identifying the foreign company with ASIC | Tax, GST and dealing with other businesses |
ACN: Australian Company Number
ASIC gives every company a unique 9-digit ACN when it is registered. If you set up an Australian Pty Ltd subsidiary, it receives an ACN on registration, usually within a day of lodging. See company formation.
ARBN: Australian Registered Body Number
If your overseas company registers to carry on business in Australia in its own name, as a branch, ASIC gives it an ARBN instead of an ACN. The company stays the same legal entity; the ARBN is its Australian registration number.
ABN: Australian Business Number
The ABN is an 11-digit number issued for tax and business purposes, not by ASIC. Companies, registered foreign companies and other entities carrying on an enterprise in Australia can apply. For a company, ASIC says the ABN is often the same as the ACN with 2 extra digits at the beginning (for example, ACN 123 456 789 becomes ABN 36 123 456 789). Without an ABN, Australian businesses that pay you may have to withhold 47% of the payment. See ABN and GST registration.
Which number goes on invoices and documents?
- Australian companies must show their name and ACN (or an ABN that contains the ACN) on the first page of public documents, such as invoices, receipts, orders, letterhead, notices and contracts (s153 Corporations Act). Business cards and envelopes are exempt.
- Registered foreign companies must show their name and ARBN on public documents and, unless they are an authorised deposit-taking institution, their place of origin and a notice of members' limited liability if their name does not end in "Limited" or "Ltd" (s601DE).
- Tax invoices for GST must also show the ABN.
Which numbers does a foreign company need?
- Australian subsidiary (Pty Ltd): an ACN from ASIC, then an ABN and TFN from the ATO.
- Branch of your overseas company: an ARBN from ASIC, then an ABN and TFN.
- Selling into Australia without a presence: possibly an ABN only, or simplified GST registration for some digital and low-value sales.
Frequently asked questions
What is the difference between an ACN and an ABN?
An ACN is the 9-digit number ASIC gives a company when it is registered. An ABN is an 11-digit number issued by the Australian Business Register for tax and business dealings. A company has both, and its ABN is often its ACN with 2 extra digits in front.
What is an ARBN?
An Australian Registered Body Number, the number ASIC gives a foreign company that registers to carry on business in Australia, and certain registered Australian bodies. It plays the same role as an ACN for a company registered overseas.
Does a foreign company need an ACN or an ARBN?
It depends on the structure. An Australian subsidiary gets an ACN. An overseas company registering a branch in Australia gets an ARBN. Both then usually apply for an ABN.
Which number must be on an invoice?
An Australian company must show its name and ACN, or an ABN that includes the ACN, on invoices and other public documents. A tax invoice for GST must also show the ABN. A registered foreign company shows its ARBN.
This content is general information only and is not legal, financial or tax advice. Laws and regulations change often. For advice on your circumstances, speak to a qualified adviser.